What is SW OD , and why should I care?

What is SW OD? Can instrumentation tubing be welded and replace double ferrule compression fittings?

If you’ve ever come across these acronyms and scratched your head, you’re in the right place. Don’t worry! Let’s unravel this mystery together.

Remember, if you’re wondering what instrumentation tubing is, I explain it in this blog.

Before anything else, here’s a quick 3-minute video where I explain what it is and how it could be the solution you’re looking for. With the right accessories, fittings, couplings, and connectors, you can weld instrumentation tubing.

SW OD: What does it really mean?

To have a better understanding of the concept, let’s start with the basics of the different acronyms:

What does SW mean?

These acronyms refer to Socket Welding, a type of welding that involves inserting the end of a pipe into a fitting or valve and then applying a weld bead at the joint. It is also known as socket weld or insert weld.

If you want to be much more informed about this type of welding and how it differs from BW (butt weld), click here.

What does OD mean?

On the other hand, these acronyms stand for Outside Diameter (OD), which refers to the external diameter of the pipe or tubing.

So… What does SW OD mean?

SW OD refers to “Socket Weld Outside Diameter”. It is a type of connection that combines the advantages of SW welding with the precision of OD tubing. Therefore, it is the term we use when referring to welding instrumentation tubing.

Why is SW OD so useful?

This type of connection is ideal for bigger sizes: When working with pipes of big diameters, where double ferrule compression connections are less common, it provides a solid and secure connection, ensuring system integrity.

Easy alignment: Inserting the tubing into fittings or sockets simplifies alignment during installation, reducing errors and assembly time.

Superior strength: SW offer high resistance to pressure and mechanical stresses.

So now you know—if you’re dealing with big tubing sizes and double ferrule fittings don’t convince you, don’t even hesitate! SW OD connections will be your best ally.

But beware! They are not only available for jumbo sizes—SW OD fittings cover the entire range of tubing sizes.

What do we offer at Redfluid?

We offer a wide range of SW OD connection products to suit your needs:

  • Straight unions: To connect pipe sections in a straight line.
  • Elbows: Perfect for changing the flow direction by 90° or 45°.
  • Tees: Ideal for diverting flow in different directions.
  • Crosses: For four-way intersections.
Straight unions
Straight union
Elbows SW OD
Male elbow
Tees
Union tee
Crosses SW OD
Union cross

And these are just a few examples of the many products we offer.

If you want to see more, here’s the catalog!

Catálogo SW OD EN

How to choose the right SW OD?

Next, I’ll show you step by step how to order, so grab your notebook and pen—here we go!

  • Step 1: First, determine what type of fitting you need (straight union, tee, elbow, etc.).
  • Step 2: Select the fitting material—I recommend reading this blog before making your choice.
  • Step 3: Choose the fitting size—as I mentioned earlier, this connection type is especially beneficial for bigger sizes.

With these three simple steps, your SW OD fitting will be correctly ordered. But wait! If you want to go the extra mile, you can also specify the working pressure and the fluids that will flow through it.

Another common application is the conversion from SW instrumentation fittings to BW piping fittings—meaning it allows transitioning from SW OD tubing (ASTM A213 or A269) to BW piping (Schedule 80 o SCH 160 type ASME B36.10/19).

Connector SW OD

Typical Applications of SW OD

“Yes, yes, Kike, all this information is great, but we want to see real examples of industries where this type of connection works well.”

Alright, alright, I’ll tell you!

The main industries using SW OD are:

  • Oil & Gas: Highly useful in high-pressure systems for transporting liquids and gases.
  • Chemical Plants: Excellent for pipelines handling corrosive or reactive fluids.
  • Energy: Found in steam systems and hydraulic circuits in power plants.

General Industry: Its versatility makes it ideal for water distribution networks, compressed air, and industrial gases

If you have any doubts or need more info about our SW OD solutions, don’t hesitate to reach out! I’m here to help you find the best option for your system.

And remember, for any questions about valves, fittings, or high-pressure systems, get in touch with me!